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Fizeau Interferometer System.
Ralon Labs (c) 2005

The goal of this project is to establish a fast reliable method to check the flattness of an optical surface down to 1/10  of a wave.  The second goal is to be able to manufacture  inexpensive retroreflectors and interferometers for the manufacturing of several components needed in the  linear scale project.

Simple device to check the flattnes of a surface.
The first test ever made with a 650nm diode laser

This is the first test of a  frequency  doubled Nd:YAG laser
The setup of this rough test.

A very crude test on a shoe string budget to see if  piezo speaker could work as piezotranslators. This test was just to prove the technology. With this device it is possible to  perform phase shift interferometry and improve the resolution.

choice of light source.

A more complex task would be to measure the surface with many wavelengths from blue 405nm laser to 670nm. this could be used to resolve several surfaces at the same time, but involve some complex maths and image computing.

A prism can easily be measured and corrected to a very high accurace by counting the fringes.
setup of a prism

basic setup

I will use a standard drilling mashine, 50 Euro type, as frame work. It works fine becouse the only important distance is the object-reference plate.



Example of  existing system: